U.S. patent application number 11/706244 was filed with the patent office on 2007-11-29 for cast flange for pipe couplings.
Invention is credited to Avi Chiproot, Eliezer Krausz.
Application Number | 20070273151 11/706244 |
Document ID | / |
Family ID | 38510319 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070273151 |
Kind Code |
A1 |
Krausz; Eliezer ; et
al. |
November 29, 2007 |
Cast flange for pipe couplings
Abstract
The invention relates to pipe couplings, and is an improvement
on a cast flange for such couplings housing. More particularly, the
invention provides an improved flange and its seal which is
attachable to the external surface of a pipe and which can be used
to eliminate a small leak if access to a pipe extremity is
available. The flange housing is also useful, again in combination
with a seal element, for anchoring an adjacent item and for
preventing fluid flow along the external surface of the pipe. The
invention provides an end clamp housing for attachment to a
cylindrical body, the side end housing being a unitary metal
casting comprising; an open annular base element provided with a
first, ingoing flange at a first side of the base element and a
second ingoing flange at a second side of the base element. The
second ingoing flange having a cross-section forming a loop
extending outwardly beyond the base element; and a pair of clamp
members projecting outwardly from the base element. The clamp
members being positioned face to face and having an aperture to
allow the insertion of a tightening element which can be operated
to reduce the distance between the two ends of the open annular
base element and thereby press an annular seal element against the
outside of a pipe inserted through the seal clamp housing, which
after release of the tightening element returns to its original
dimensions.
Inventors: |
Krausz; Eliezer; (Tel-Aviv,
IL) ; Chiproot; Avi; (Kfar-Saba, IL) |
Correspondence
Address: |
PEARL COHEN ZEDEK LATZER, LLP
1500 BROADWAY 12TH FLOOR
NEW YORK
NY
10036
US
|
Family ID: |
38510319 |
Appl. No.: |
11/706244 |
Filed: |
February 15, 2007 |
Current U.S.
Class: |
285/406 |
Current CPC
Class: |
F16L 17/04 20130101;
F16L 55/172 20130101; F16L 21/022 20130101 |
Class at
Publication: |
285/406 |
International
Class: |
F16L 23/00 20060101
F16L023/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2006 |
IL |
175971 |
Claims
1. A flange seal clamp housing for attachment to a cylindrical
body, particularly to a pipe, said housing being a unitary metal
casting comprising: a) an open annular base element provided with a
first, ingoing flange at a first side of said base element and a
second ingoing flange at a second side of said base element, said
second ingoing flange having a cross-section forming a loop
extending outwardly beyond said base element; and b) a pair of
clamp members projecting outwardly from said base element, said
clamp members being positioned face to face and each having an
aperture to allow the insertion of a tightening element
therethrough, which can be operated to reduce the distance between
the two ends of said open annular base element and thereby press an
annular seal element against the outside of a pipe inserted inside
said seal clamp housing, said housing after release of said
tightening element returning to its original dimensions.
2. The flange seal clamp housing as claimed in claim 1, wherein
said metal casting is molded from cast iron.
3. The flange seal clamp housing as claimed in claim 2, wherein
said cast iron is of the nodular type.
4. The flange seal clamp housing as claimed in claim 1, in
combination with a sealing element inserted therein.
Description
FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates to pipe couplings, and is an
improvement on a cast flange for such couplings housing.
[0002] More particularly, the invention provides an improved flange
and its seal which is attachable to the external surface of a pipe
and which can be used to eliminate a small leak if access to a pipe
extremity is available. The flange housing is also useful, again in
combination with a seal element, for anchoring an adjacent item and
for preventing fluid flow along the external surface of the
pipe.
[0003] Pipe couplings and the clamps associated therewith are well
known and have been manufactured by the present inventors for some
years. The coupling comprises a central body member and two side
clamps. A prior-art clamp is illustrated in FIG. 1. However there
has now been found an improved manufacturing method which at the
same time allows a design improvement and cost reduction of this
item.
[0004] No directly relevant US patents were found. A 2-part seal
clamp assembly for piping is disclosed by Friedrich et al. in U.S.
Pat. No. 5,692,544, the purpose of which is to contain leakage
between the large diameter end flanges of adjoining co-axial pipes.
Devices intended to seal pipe leaks are seen in US Patent
Applications 2001/0008149 by D{grave over ( )}auria, No.
2004/0108010 by Gaston et al, and No. 2004/0118467 by Pirart. These
disclosures do not however relate to the type of seal clamp which
is the subject of the present invention.
[0005] A disadvantage of presently known end clamps of the steel
band type is that the areas adjacent to the lug of the seal clamp,
at each side are unflexible, straight and not concave, when viewed
parallel to the seal clamp axis, whereas the seal operates better
when pressed inwardly by a concave surface. This defect in band
clamps could be due to the nature of bending machines, the first
and the last portion of a metal strip being curved not being bent,
and remaining as flat as the original metal strip, probably because
at the beginning and at the end of the bending process the
workpiece is in contact with only 2 of the 3 rollers of the bending
machine.
[0006] In a coupling of the type seen in FIG. 1 of the prior art
design, and also in U.S. Pat. No. 4,463,975 to McCord, a sudden
increase in thickness of the band when approaching the area of the
lug is seen. This thickness results in sharp loss of flexibility
near the lug, the outcome of which is that when in use this section
will retain its original flat shape and thus fail to conform to the
circular seal. More sealing pressure is thus required before a
pressure-tight condition prevails. Applying high sealing pressure
delays work on site and shortens the life of the flexible seal.
OBJECTS OF THE INVENTION
[0007] It is therefore one of the objects of the present invention
to obviate the disadvantages of prior art seal clamps and to
provide an improved and lower cost external flange seal clamp
housing of the type where the pipe diameter is known in advance,
and where access to a pipe end is available.
[0008] It is a further object of the present invention to provide a
housing the width of which can be controlled more easily to conform
accurately to the cross-section of the flexible seal element being
held therein.
SUMMARY OF THE INVENTION
[0009] The present invention achieves the above objects by
providing an end clamp housing for attachment to a cylindrical
body, said side end housing being a unitary metal casting
comprising:
[0010] a) an open annular base element provided with a first,
ingoing flange at a first side of said base element and a second
ingoing flange at a second side of said base element, said second
ingoing flange having a cross-section forming a loop extending
outwardly beyond said base element; and
[0011] b) a pair of clamp members projecting outwardly from said
base element, said clamp members being positioned face to face and
having an aperture to allow the insertion of a tightening element
which can be operated to reduce the distance between the two ends
of said open annular base element and thereby press an annular seal
element against the outside of a pipe inserted through said seal
clamp housing, which after release of said tightening element
returns to its original dimensions.
[0012] Two such end clamps being used with the cylindrical body of
the coupling.
[0013] In a preferred embodiment of the present invention there is
provided a seal clamp housing as wherein said metal casting is
molded from cast iron.
[0014] In a further preferred embodiment of the present invention
there is provided an end side clamp housing wherein said cast iron
is of the nodular type.
[0015] In another preferred embodiment of the present invention
there is provided a seal clamp housing in combination with a
sealing element inserted therein.
[0016] A surprising discovery made while research was in progress
is that cast iron is a suitable choice for use in casting the seal
clamp housing described. As the annular seals are made in fixed
diameters according to the outer dimension of standard pipes, there
is no need for the housing to be applied to a wide variation of
diameters. Cast iron can be cast into the intricate shapes seen in
the diagrams. The advantages are:
[0017] a) satisfactory corrosion resistance even if left
uncoated;
[0018] b) cast iron is a similar metal to the steel pipes and steel
pipe fittings with which contact could occur, thus eliminating
electrochemical corrosion;
[0019] c) a material rigid enough to resist sideways pressure of
the compressed seal element;
[0020] d) excellent long-term retention of elastic properties that
ensures spring-back to original dimensions after extended time of
use and so allows easy axial removal of the pipe to which it had
been clamped; and
[0021] e) low cost of material and low labor costs in
production.
[0022] It has been found that the cast-iron flange clamp is no
heavier than the sheet steel clamp which it now replaces. This is
due to the use of thin walls reinforced by ribs on the outer face
of the new clamp body.
[0023] It will be further noted that advantage has been taken of
the casting process to permanently mark data, such as nominal size,
manufacturers name, part number and the like, on the component by
integral casting of raised indicia, in a permanent and very
cost-effective manner.
SHORT DESCRIPTION OF THE DRAWINGS
[0024] The invention will now be described further with reference
to the accompanying drawings, which represent by example preferred
embodiments of the invention. Structural details are shown only as
far as necessary for a fundamental understanding thereof. The
described examples, together with the drawings, will make apparent
to those skilled in the art how further forms of the invention may
be realized.
[0025] In the drawings:
[0026] FIG. 1 is a partially-sectioned elevation of a prior-art
welded-on first end lug of an end side clamp housing and its
non-sectioned second end;
[0027] FIG. 2 is a partially-sectioned elevation of a welded first
end lug of an end side clamp housing and its non-sectioned second
end, according to the invention;
[0028] FIG. 3 is a perspective view of a preferred embodiment of
the end clamp housing according to the invention;
[0029] FIG. 4 is a photographic view of the embodiment seen in FIG.
3, wherein the thinned out section in the lug area is seen
clearly;
[0030] FIG. 5 is a partially-section side view showing a seal
element inside the clamp housing, and
[0031] FIG. 6 is a partially-sectioned plan view of the same;
[0032] FIG. 7 is a perspective illustration of an assembled
coupling; while
[0033] FIG. 8 is a cross section thereof.
FULL DISCLOSURE OF THE INVENTION
[0034] There is seen in FIG. 1 a part of a prior-art seal clamp
housing 10 provided with welded-on end lugs 12. The lugs 12 are the
source of a sudden increase in thickness of the band 14 when
approaching the area of the lugs 12. This thickness results in
sharp loss of flexibility near the lug, the outcome of which is
that this section 16 retains its original flat shape and thus fails
to conform to the shape of the circular seal 18. More sealing
pressure is thus required before a pressure-tight condition
prevails. The flat portion 16 of the clamp housing 10 also causes a
reduction of the maximum diameter pipe which can be inserted in the
seal inner diameter.
[0035] It has also been observed that the sides of the seal 18 do
not contact the inner face of the channel walls 20 in the section
proximate to the lugs 12.
[0036] Referring now to FIG. 2, there is seen a preferred
embodiment of the flange seal clamp housing 22 according to the
invention. In practice two such housing being used as seen in FIG.
7.
[0037] The seal clamp housing 22 is seen holding a flexible
circular seal 18. These components 22, 18 are used for attachment
to a cylindrical body, particularly to a pipe, not seen. The
housing 22 is manufactured as a thin-wall unitary metal casting.
The walls are reinforced by integral ribs 30.
[0038] Details of the cross-section of the housing 22 will be
provided with reference to FIGS. 6 and 8.
[0039] A pair of clamp members or lugs 24 project outwardly from
the housing extremities. The clamp members 24 are positioned face
to face, and each is provided with an aperture 26 to allow the
insertion therethrough of a tightening element such as a screw,
nut, and washers as seen in FIG. 7. Tightening thereof reduces the
distance between the two clamp members 24 and thereby exerts almost
360.degree. radial pressure on the annular seal element 18 against
the outside of a cylindrical body or pipe (not seen) inserted
through the seal clamp housing 22. On release of the tightening
element the housing 22 springs back to its original dimensions to
form an opening through which an existing pipe can be removed
without obstruction, and a new pipe installed.
[0040] The casting method was further utilized to strengthen the
clamp members 24, and as a result are now suitable for accepting
higher closure forces.
[0041] Both clamp members 24 have a reduced thickness area 28,
which improves flexibility in this region.
[0042] The preferred metal for the casting is cast iron. The
nodular type is preferred as being more crack resistant. The
advantages of this unusual choice have been detailed previously.
Briefly, corrosion resistance, strength, rigidity, low cost and
long-term retention of spring-back were the main
considerations.
[0043] With reference to the rest of the figures, similar reference
numerals have been used to identify similar parts.
[0044] FIG. 3 illustrates the whole flange housing 22. The reduced
thickness area 28 is seen clearly inside a clamp member 24. The
figure also shows the strengthening ribs 30 and the marking
letters/digits 32 which are integrally cast.
[0045] Turning now to FIG. 4, there is presented a photographic
view of the housing 22 carrying a circular seal 18. A more detailed
view of the same embodiment is seen in FIG. 5, which shows the seal
element 18 inside the clamp housing 22.
[0046] With reference now to FIG. 6 there is seen the profile of
the clamp housing 22. The profile has an open annular base element
34 provided with a first, ingoing flange 36 at a first side of the
base element 34. A second ingoing flange 36 is seen at a second
side of the base element 34. A second ingoing flange 38 has a
cross-section forming a loop 40 extending outwardly beyond the base
element 34.
[0047] Referring now to FIGS. 7 and 8 there are seen two side
housing 22 being connected to cylindrical body 40 forming the
coupling. Lugs 24 are tightened by bolts 42.
[0048] The scope of the described invention is intended to include
all embodiments coming within the meaning of the following claims.
The foregoing examples illustrate useful forms of the invention,
but are not to be considered as limiting its scope, as those
skilled in the art will be aware that additional variants and
modifications of the invention can readily be formulated without
departing from the meaning of the following claims.
* * * * *